Objective:To observe the affection of angiotensin Ⅱ antagonists on the cultured subtype 2 receptor of angiotensin II transfected aortic vascular smooth muscle cells of rat.Methods:After transfected the plasmid that contained the cDNA of subtype 2 receptor of angiotensin II into cultured rat vascular smooth muscle cells, the cells were divided into three groups：cells of group 1 were treated with angiotensinⅡ,cells of group 2 were treated with angiotensinⅡand losartan,cells of group 3 were treated with angiotensinⅡ and PD123319 .After experiments，the expression of PCNA, NOS and the cell number was tested, respectively.Results：After treated with Losartan，the cell number of group 2 was(4.17±0.15)×105，the OD value of PCNA was 0.202 6±0.007 6，both of which were less than that of cells of group 3；the OD value of NOS of cells was more in group 2(0.027 5±0.002 1 ) than that in group 3 (0.016 9±0.002 0) (P＜0.01).Conclusions:It suggests that when being activated,subtype 2 receptor of angiotensin Ⅱ could inhibit the proliferation of vascular smooth muscle cells and antagonist the effect of subtype 1 receptor of angiotensin Ⅱ,such an effect may be related to the activation of NOS.